1. Field of the Invention
This invention relates to a chip component to be mounted vis-a-vis on a print substrate by means of a mounter, said chip component being capable of holding a probe for examination.
2. Prior Art
A chip component having a configuration as illustrated either in FIG. 4(A), 4(B) or 4(C) and comprising a solderable metal plate 42 and a not solderable metal plate 41 is disclosed in Japanese Utility Design Application No. 62-186544.
A chip component as described above is mounted and soldered on a print substrate 61 as shown in FIG. 6 for holding a terminal 62 of a probe for examination of the voltage and the electric current applied to the printed substrate. For mounting a chip component of this prior art on a substrate for probing printed circuits, chip component 50 is taken up by a nozzle 51 for positioning and then placed on the right position, Once chip component 50 is mounted, light is shed on it from a light emitting member 52 to form its shadow, which is detected by a light sensing element 53 to determine if the chip is correctly mounted. In this prior art, the rays from the light emitting member perpendicularly strike the anchoring surface of the chip component. (See FIG. 5(A) A.) It should be noted, however, that the light connecting the light emitting member and the light sensing element can be either parallel to the longer edges of anchoring surface 54 of chip component 50 for circuit probe (FIG. 5(B) B) or parallel to the shorter edges of anchoring surface 54 of chip component 50 (FIG. 5 (B) C). With chip component 50 for circuit probe of this type, when the line connecting the light emitting member and the light sensing element is perpendicular to anchoring surface 54 of chip component 50 (FIG. 5(B) A) and when the line is parallel to the longer edges of the anchoring surface (FIG. 5(B) B), the light emitting member forms a shadow of chip component 50 which is large enough to be detected by the light sensing element. However, when the line between the light emitting member and the light sensing element is parallel to the shorter edges of anchoring surface 54 of chip component 50, the light coming out from the light emitting member strikes only the area of chip component 50 immediately under the nozzle and forms a shadow of the component only for its thickness (preferably approximately 0.3 mm), which is by no means large enough to be detected by the light sensing element. In order to avoid this problem and make it compatible with a mounter of any type, a chip component of this prior art, which is used for circuit examination, has to be formed from a metal plate having a considerable thickness (0.4 mm or more). Now referring to FIG. 3(A), chip component 31 having a thickness as described above is taken up by nozzle 51 by anchoring surface 32 for positioning and then placed on its correct position. Once it is placed, light is shed on lateral side 33 of the metal plate of chip component 31 next to anchoring surface 32 to form its shadow, which is detected by light sensing element 53. Since lateral side 33 has a relative large width, the shadow thus formed is large enough to be detected by the light sensing element to ensure that chip component 31 is correctly mounted. FIG. 3(B) shows a sectional view of chip component 31 for circuit examination, in which as in the case of the chip component shown in FIG. 4 outer surface 35 is made of a solderable metal while inner surface 34 is made of a not solderable metal.
Chip component 31 for circuit examination which is made of a relatively thick metal plate (0.4 mm or more) has certain drawbacks. Firstly, a thick metal plate to be used as a material for producing such components is poorly workable in a press machine as compared with a relatively thin metal plate. Secondly, a chip component made from such a thick metal plate inevitably has an increased height, which makes the component less stable in its mounted position. Thirdly, such a component needs more material and accordingly cost more than a component made of a thin metal plate.